Specify a WHERE clause
You can specify a WHERE clause as one of the following:
•An SQL predicate
•A logical expression
•A compound logical expression
A WHERE clause cannot contain a function.
Specifying an SQL predicate
An SQL predicate is a condition that evaluates to true, false, or unknown.
To specify a WHERE clause that is an SQL predicate:
1. Specify the left operand of the SQL predicate.
2. Select the keyword operator of the SQL predicate.
3. Specify the right operand of the SQL predicate, if any.
a. If the right operand is a value, type the value in the field.
b. If the right operand is a nested SELECT statement:
1. From the Unary operator menu, select Right operand > Nested SELECT, and then the type of nested SELECT statement you want to use.
c. If the SQL predicate has additional operands or keywords, type them in the field.
d. To apply a unary operator to the right operand you have specified, from the Unary operator menu, select Right operand and then the unary operator you want to apply.
Example:
•(EMPLOYEE.STATUS IS NULL)
•(EMPLOYEE.NAME LIKE 'JOHN%')
•(WAGES.SALARY BETWEEN 2000 AND 3000)
Specifying a logical expression
A logical expression is mathematical condition that evaluates to true, false, or unknown.
To specify a WHERE clause that is a logical expression:
1. Specify the left operand of the logical expression.
a. To apply a unary operator to the left operand you have specified, from the Unary operator menu, select Left operand and then the unary operator you want to apply.
2. Select the logical operator of the logical expression.
3. Specify the right operand of the logical expression.
a. If the right operand is a value, type the value in the field.
b. To apply a unary operator to the right operand you have specified, from the Unary operator menu, select Right operand and then the unary operator you want to apply.
Example:
•(EMPLOYEE.NUMBER = WAGES.EMPNUMBER)
•(MIN(EMPLOYEE.AGE) > 40)
Specifying a compound logical expression
A compound logical expression is a logical expression that consists of a combination of expressions, SQL predicates, or other logical expressions.
To specify a WHERE clause that is a compound logical expression:
1. Specify one of the expressions or logical expressions contained in the compound logical expression by following the same steps as for specifying a WHERE clause that is a logical expression.
1. If you are specifying an expression, select a binary operator instead of a logical operator when following the steps for specifying a WHERE clause that is a logical expression.
2. Select Add to operand lists.
3. Repeat the steps above for each expression or logical expression contained in the compound logical expression.
4. Specify the left operand of the compound logical expression.
a. If the left operand is an expression you specified using the first two steps above, select it from the list.
b. To apply a unary operator to the left operand you have specified, from the Unary operator menu, select Left operand and then the unary operator you want to apply.
5. Select the logical operator of the compound logical expression.
6. Specify the right operand of the compound logical expression.
a. If the right operand is an expression you specified using the first two steps above, select it from the list.
b. If the right operand is a value, type the value in the field.
c. To apply a unary operator to the right operand you have specified, from the Unary operator menu, select Right operand and then the unary operator you want to apply.
Example:
((WAGES.SALARY - WAGES.TAXES) > 3000) AND NOT (EMPLOYEE.AGE < 40)
Specifying an empty expression
To specify an empty expression for the WHERE clause:
1. If an operator is specified in the Operator field, select <none> from the list.
2. If an operand is specified in the Left operand field, delete it.
The Expression field should now be empty.
Last modified date: 08/13/2019